Ya I'm trying to destroy the "spr_crops" I don't know how to destroy the instance "spr_crops" I think I have to set it up in the script that is in the second picture.
I'm assuming you are sticking to the usual naming conventions here and that the "spr_" prefix signifies that the resource is a sprite?
If so, then you can't destroy sprites, you need to destroy the instance of the object as you just said.
In the second image you create an instance and store it in a variable called "inst", and then you store that inside a grid (which I assume matches the position of the tiles or grid of your level).
So logically and working backwards from that, to destroy that instance you would need to find what cell of the grid the cursor is in when the right mouse button is clicked, and then with that information you can destroy the instance stored in that grid position.
if you created an instance of the object obj_crop, and wanted to destroy it ,the logic thing to do would be to destroy the same object called obj_crop, not the sprite spr_crops
That would be logical by following the prefixes, but that would destroy every instance of obj_crops rather than the specific instance that was being clicked on.